Trigger 92 Description

Sequence: C27
Trigger 92 ( Aurora/SKR Mode, inside source region )

This mode is designed to provide a survey mode with DF-2 (direction-finding with 2 antennas), and additionally provide high frequency & time resolution for a narrow band in the SKR frequency region to resolve fine structure.

Both low and high frequency WFR measurements are made. In high-frequency mode, there are 512 samples taken for the EX and EW antennas. These channels are also analyzed onboard using the LFDR FFT software, and the LFDR data is provided in addition to the waveform data. In low-frequency mode, 5-channel 2048-sample WFR measurements are made every 32 seconds.

Langmuir Probe sweeps are performed every 32 seconds; density measurements are made at a 100-Hz sampling rate to match the Low-Frequency WFR measurements. A simple up-going ramp sweep is performed; with a future software update, this will become a down-going voltage ramp.

A Sounder measurement is scheduled every 5 minutes.

Receiver Frequency Range Sensors Time between Snapshots
LFR 0.1 - 2.5 KHz EX, EW 160 seconds
MFR 25 - 12 KHz EX, BZ 32 seconds
WFR(LF) 1 - 25 Hz EX,EW,BX,BY,BZ 32 seconds
WFR(HF) 0.1 - 2.5 KHz EX,EW 160 seconds
HFR 3.6 KHz - 16 MHz EX, EW 11.875 seconds
LP N/A Langmuir Probe 32 seconds
Sounder 3.6 - 115 KHz EX, EW 300 seconds

The HFR is in SKR mode, with freeze mode for H1. The freeze frequency is by default 325 KHz, but this can be tweaked. This mode is defined by:
          Correlations     Channels        Integ.                Size Frequency
Band Ant. Auto-  Cross-    per Band   df   Period    Rep   Steps kHz  Start - Stop
---- ---- -----  ------    --------   --   ------    ---   ----- ---- ------------
ABC  2E   y         y        16       n    125       1                3.6-319 kHz
H1   2E   y         y         8       n    20        100   1     0    325k
H2   2E   y         y         1       n    20        1     315   50   325kHz-16MHz
Bands ABC require 0.395 sec to complete, H1 requires 2.74 sec, and H2 requires 8.25 sec for a total of 11.39 sec per sweep. However, the time between analyses is 11.875 seconds. Every 300 seconds the HFR normal analyses are replaced by a Sounder analysis. The Sounder operation has a duration of approximately 40 seconds. This Sounder analysis is defined by:
  sounder mode:   EZ AAA
  1st  sounder freq:      0
  last sounder freq:     89
  T1 delay:        10 msec
  T2 delay:        25 msec
  T3 delay:        25 msec
  passive spectra:      2
  active  spectra:      2
  # of cycles:       1
  sounder output A:      3 autos
  sounder output B:      3  AGCs